As is known in the art, after product (typically circuit boards) have been brought up to a high enough temperature to be reflow soldered, they need to be cooled. Typically, this cooling after reflow soldering requires a large cooling section including fans, heat exchangers, cooling water, cooling towers, and chillers or various combinations of these devices. Additionally, as solder is reflowed effluents such as flux contaminates are released into the atmosphere of the furnace. These flux contaminates can condense and collect on the heat exchangers, fans and product, requiring cleaning and maintenance of the parts of the conventional type furnaces and coolers.
Vortex tubes provide one manner of cooling. A vortex tube accepts compressed gas at an inlet which is obliquely disposed with respect to the tube body. The compressed gas enters the tube body at an angle and rapidly rotates helically towards an end. As a result of the rapid helical rotation of the gas (for example at approximately one million revolutions per minute), a vortex is produced within the tube in which the inner region of rotating gas is expanding and compressing the outer region of rotating gas. Thus, the outer region of rotating gas is acquiring heat from the inner region of rotating gas. At one end of the tube body a diaphragm has an opening which allows the hot, outer region of gas to escape, thereby providing a hot gas output stream, while redirecting the inner region of gas back through the tube. The opposite end of the tube body has a diaphragm which has an opening which allows the cold gas to escape, thereby providing a cold gas output stream. U.S. Pat. No. 1,952,281 issued to Joseph Ranque on Mar. 27, 1934 for a "Method and Apparatus for Obtaining From a Fluid Under Pressure Two Currents or Fluids at Different Temperatures", U.S. Pat. No. 3,208,229 issued to C. D. Fulton on Mar. 16, 1965 for a "Vortex Tube" and U.S. Pat. No. 3,173,273 issued to C. D. Fulton on Sep. 28, 1965 for a "Vortex Tube" disclose in greater detail a vortex tube, and Applicant hereby incorporates by reference these disclosures.
Vortex tubes have been used in variety of devices. U.S. Pat. No. 4,407,134 to Snaper discloses the use of vortex tubes in an air conditioning system, U.S. Pat. No. 5,344,478 to Zurecki et al. discloses the use of a vortex tube to cool molten metal, and U.S. Pat. No. 4,714,484 to Kuhl et al. discloses the use of a vortex tube in an IR Spectrophotometer.